During the development of oil fields, the physical properties of reservoirs, microscopic pore structure and heterogeneity are changed with the development of water injection. It is of importance to build a 4 D geological model reflecting the dynamic variation of reservoir properties for recognizing reservoir geological characteristics, predicting the distribution of remaining oil and raising effectiveness in the exploitation of oil fields. Using core, logging and lab analytic data, and taking the reservoir model of member 3 of the Shahejie Formation in eastern Hebei Province for example, this paper studies the variation rule of reservoir parameters during the course of water injection, builds a 3 D reservoir geological model for different development stages by means of stochastic simulation, and makes a useful trial for building a 4 D reservoir geological model, which has gained good effects in practical application to oil fields.